3 Virtual Diagnostics Network

Transcript

Hello!!Welcome to the third talk of the week and i.e Virtual diagnostics and network. Plant is always at risk because of several reasons one of the most significant reason is plant pathogen. And some of them be originated in the same level, or same area or whereas, some of them has been identified to be coming from a distant places or from a newer, another country. So, it is always important to have a knowledge base on most potential threats to crop plants because if the pathogen is not existing earlier in a particular area people may not be aware of the pathogen which maybe of quarantine significance from of that area without proper database or without a proper tool to go for identification. So, in this context virtual diagnostic networks come into play a big role and it helps the growers and decision makers into a great extent.

Plant Health Risk

The containment and mitigation of exotic plant pathogens are dependent upon early detection and accurate diagnoses also in a timeframe to enable effective response. Increase dependency on international trade to address global economic and food security challenges pathogen incursion will also continue. But a question arises is that do we have a rational plant biosecurity strategy and adequate plant biosecurity infrastructure to protect plant systems from the pathogens that threaten the plant health? The emergence of hybrid Phytophthora species has been reported as a consequence of the global trade in nursery and landscape plants. Of great concern is that the host range and aggressiveness of the hybrid Phytophthora species were not predicted based on the parental phenotypes. OS, where situation like this occurs then it is definitely useful to have a broader database or broader level of information to actually detect and identify and diagnose the appropriate problem that is associated with the plant disease. Similarly, novel virulence patterns in plant pathogenic bacteria have been attributed to horizontal gene transfer (HGT). The global movement of plants may provide more opportunity for HGT among plant pathogenic bacteria creating challenges for plant health in general, and plant diagnostics, in particular. So, when a bacteria acquire a new gene from a closely associated or bacteria, then bacteria turns out to be a different variant from the original strains that are present in a particular locality and that is a bigger challenge again to identify such pathogens with genetical variations and for this we need to have informations on this regard. The ability of cryptic satellites to alter the host range of Gemini viruses may present new challenges to plant health and confound our ability to diagnose and mitigate these new virus diseases. So, this shows that whether it is a hybrid fungal pathogen, or whether it is a horizontal gene transferred pathogenic bacteria or whether it is a satellite variated changes in viruses. These all possible occurrences of new strains of viruses , fungi and bacteria could help us to identify based on the existing database that is available that can guide somebody to help and diagnose the problem. The

Need for Robust Plant Diagnostic Systems

So there is need for The Need for Robust Plant Diagnostic Systems. With respect to trade, the mere presence of a pathogen can stop shipments whether or not the disease was manifested. Being able to accurately identify a pathogen and diagnose a disease is essential to ensure proper disease mitigation measures are implemented and to ensure that correct trade decisions are made. So, mere detection of a pathogen in a shipman can stop the shipman from moving from the port and it may cause a severe or tremendous loss to the to the industry or to the traders but a quick decision is required to be obtained to minimise such kind of losses. With respect to sensitivity, specificity, and robustness, the stringency of diagnostic technologies and protocols vary across the continuum from pre-infection detection to post-outbreak monitoring. So it is highly essential for: Prevention, Early Detection and Accurate Diagnoses, and Response and Recovery and this can be achieved when we have a very robust plant diagnostics system.

Virtual Plant Diagnostic Networks

Virtual Plant Diagnostic Networks can play a bigger role in this aspect: A global network of plant diagnostic infrastructure is needed to facilitate the detection, diagnosis, and management of recurrent, emergent, and introduced plant pathogens. So data that is available in one part of the globe, if it is not shared with the other part of the globe then if a new pathogen emerges in a new locality, then they have to face a greater challenge to identify the pathogen. But if the data is shared then very quickly one can go for proper diagnosis and other identification of the possible plant pathogen. Trade increases the risk to plant health as a direct result of the movement of unwanted plant pathogens and pests. The International Plant Protection Convention (IPPC) requires that signatory nations abide by strict Sanitary and Phytosanitary (SPS) standards to minimize the movement of plant pathogens and pests across national boundaries. However, the systems to ensure that only pathogen-free plants are put into global distribution chains are overwhelmed by the massive volume of plants that are shipped over great distances in short period of time. So, its a big challenge and in a global trading system a huge amount of plant material being shipped in a very shorter time frame so to detect and diagnose time frame moving along with those plant samples is a very very tough job.

Plant Diagnostic Networks

Plant Diagnostic Networks has been developed. In 2002, the Land Grant University (LGU) system in the U.S. partnered with the United States Department of Agriculture to create the National Plant Diagnostic Network (NPDN) to increase the capability and capacity of plant diagnostics throughout the U.S. This mission of NPDN is to promote the early detection of plant pathogens and pests by training first detectors and ensuring accurate and rapid diagnosis. The U.S. Agency for International Development partnered with a few LGUs to create the International Plant Diagnostic Network (IPDN) to extend this concept to nations where limited diagnostic resources are available. So, it is a very good initiative in the sense that the Land Grant Universities along with the USDA in United States of America created the National Plant Diagnostic Networks and they have extended this network to a global platform in the International Plant Diagnostic Networks which can be used by those nationa’s where limited diagnostics resources are available.

The Global Plant Clinic (now called PlantWise) was created by CABI to bring plant diagnostic support to rural communities in low income nations. PlantWise has offered on-site clinics in rural settings in South America, Asia, and Africa and where internet connectivity exists, PlantWise offers on-line digital diagnostic support from the United Kingdom itself. So, again it is a global platform that is known as PlantWise. It is giving service to Southern America, Asia, and African countries and where plant doctors are going to the farmers, meeting them and helping them to diagnose the problems and they can also give service right from the United Kingdom if the internet connection is available at the local level. The European Union Framework programs funded multinational efforts to create a virtual biosecurity research and diagnostic network for Europe. The concept is to link researchers and diagnosticians across Europe to a mutually beneficial network to enhance plant diagnostic capabilities and providing first detectors in the field with access to information necessary to ensure early detection of emerging or introduced plant pathogens. So, Plant Health Australia is working to establish a national plant diagnostic network with many of the same goals as the other networks. Scientists in Australia have created an on-line plant biosecurity toolbox (http://old.padil.gov.au/pbt/) to provide access to diagnostic resources and have already deployed a digital diagnostics system (http://www.padil.gov.au/Rmd) for Australia that now extends that capability into Southern Asia. So, apart from United States or United Kingdom, it is the European Union along with Australia that all are developing global platforms and these platforms are helping and reaching to small farm holders and helping them to make decision on their farm side to take appropriate control measures for saving their crops.

Magnitude of the Challenge for Plant Diagnostics

So, Plant diagnosticians have responsibility for a vast diversity of host plant species often spanning four levels of taxonomic complexity (e.g., varieties, species, genera, families). Each one of these plant species has a vast diversity of pathogens that cause an array of diseases, each with its own set of host specificity and ever-changing systematic of the pathogens. So, these causes a heavy problem for the plant diagnosticians because they have deal with a vast varieties of plants, and vast varieties of pathogen that are specific to certain hosts and they are not having bought hosts rents. So, they need to have been better equipped in terms of knowledge and information about those plant systematic as well as microbial systematic. Plant diagnostic laboratories at air and sea ports have enormous challenges with respect to the number of shipments, the number of samples to be processed, and the very short timeframes within which diagnoses must be rendered. So, its again a big challenge that in sea and airports huge number of samples comes and the diagnosticians have to perform the diagnostic tests of this large number of sample within a very short span of time. Some plants and plant products have short shelf lives and consequently, any delays can decrease the value of the plants. So, this is another challenge to how to deal with such plants or plants products which has very low shelf life. So, therefore a concept of life Virtual International Plant Diagnostic Network has come up.

Concept for a Virtual International Plant Diagnostic Network (VIPDN)

Few national and regional plant diagnostic networks are functioning very well and connecting those national and regional networks through a virtual international plant diagnostic network (VIPDN) is proposed. The mission and function of a VIPDN was: to provide a mechanism to facilitate the exchange of non-trade sensitive diagnostic information and resources, and to provide a vehicle for cooperation among plant diagnosticians around the world, and to provide a directory of plant diagnostic laboratories to facilitate interaction with the global research community. So, the concept of virtual international plant diagnostic network is highly appreciated as it has given the opportunities to the people concerned to have information at global level. Any information that is available at any corner of the world can be accessed through this platform. Sharing of plant diagnostic information and expertise around the world would be of great value to the international plant diagnostic community. A VIPDN could be the platform for sharing diagnostic resources such as images of symptoms, primer and probe sequences, the advantages and limitations of specific diagnostic protocols, technological expertise, and so on. So, virtual diagnostic network is now becoming a reality. And now it has to be a question of time that how it is linked to all the available databases so that access of all the available resources could be made from all the corner of the world. So, with this we have seen that how virtual diagnostic network are going to help us in future to detect, identify and diagnose the pathogens or its biomars or its specific strains and then with this informations the growers can be really be helped by providing adequate resources and management practices to the crops that are suffering from a particular plant, pest or pathogen. With this we have come to an end of this talk of virtual diagnostic network. In the next talk, we will talk about ‘Use of Airborne Inoculum for Detection and Disease Management’ decisions. Till then…

Thank you very much.